int
DRead(struct dcache *adc, int page, struct DirBuffer *entry)
{
/* Read a page from the disk. */
struct buffer *tb, *tb2;
struct osi_file *tfile;
int code;
AFS_STATCNT(DRead);
memset(entry, 0, sizeof(struct DirBuffer));
ObtainWriteLock(&afs_bufferLock, 256);
#define bufmatch(tb) (tb->page == page && tb->fid == adc->index)
#define buf_Front(head,parent,p) {(parent)->hashNext = (p)->hashNext; (p)->hashNext= *(head);*(head)=(p);}
/* this apparently-complicated-looking code is simply an example of
* a little bit of loop unrolling, and is a standard linked-list
* traversal trick. It saves a few assignments at the the expense
* of larger code size. This could be simplified by better use of
* macros.
*/
if ((tb = phTable[pHash(adc->index, page)])) {
if (bufmatch(tb)) {
ObtainWriteLock(&tb->lock, 257);
tb->lockers++;
ReleaseWriteLock(&afs_bufferLock);
tb->accesstime = timecounter++;
AFS_STATS(afs_stats_cmperf.bufHits++);
ReleaseWriteLock(&tb->lock);
entry->buffer = tb;
entry->data = tb->data;
return 0;
} else {
struct buffer **bufhead;
bufhead = &(phTable[pHash(adc->index, page)]);
while ((tb2 = tb->hashNext)) {
if (bufmatch(tb2)) {
buf_Front(bufhead, tb, tb2);
ObtainWriteLock(&tb2->lock, 258);
tb2->lockers++;
ReleaseWriteLock(&afs_bufferLock);
tb2->accesstime = timecounter++;
AFS_STATS(afs_stats_cmperf.bufHits++);
ReleaseWriteLock(&tb2->lock);
entry->buffer = tb2;
entry->data = tb2->data;
return 0;
}
if ((tb = tb2->hashNext)) {
if (bufmatch(tb)) {
buf_Front(bufhead, tb2, tb);
ObtainWriteLock(&tb->lock, 259);
tb->lockers++;
ReleaseWriteLock(&afs_bufferLock);
tb->accesstime = timecounter++;
AFS_STATS(afs_stats_cmperf.bufHits++);
ReleaseWriteLock(&tb->lock);
entry->buffer = tb;
entry->data = tb->data;
return 0;
}
} else
break;
}
}
} else
tb2 = NULL;
AFS_STATS(afs_stats_cmperf.bufMisses++);
/* can't find it */
/* The last thing we looked at was either tb or tb2 (or nothing). That
* is at least the oldest buffer on one particular hash chain, so it's
* a pretty good place to start looking for the truly oldest buffer.
*/
tb = afs_newslot(adc, page, (tb ? tb : tb2));
if (!tb) {
ReleaseWriteLock(&afs_bufferLock);
return EIO;
}
ObtainWriteLock(&tb->lock, 260);
tb->lockers++;
ReleaseWriteLock(&afs_bufferLock);
if (page * AFS_BUFFER_PAGESIZE >= adc->f.chunkBytes) {
tb->fid = NULLIDX;
afs_reset_inode(&tb->inode);
tb->lockers--;
ReleaseWriteLock(&tb->lock);
return EIO;
}
tfile = afs_CFileOpen(&adc->f.inode);
code =
afs_CFileRead(tfile, tb->page * AFS_BUFFER_PAGESIZE, tb->data,
AFS_BUFFER_PAGESIZE);
afs_CFileClose(tfile);
if (code < AFS_BUFFER_PAGESIZE) {
tb->fid = NULLIDX;
afs_reset_inode(&tb->inode);
tb->lockers--;
ReleaseWriteLock(&tb->lock);
return EIO;
}
/* Note that findslot sets the page field in the buffer equal to
* what it is searching for. */
ReleaseWriteLock(&tb->lock);
entry->buffer = tb;
entry->data = tb->data;
return 0;
}
/*!
* Handles all the reconnection details:
* - Get all the details about the vnode: name, fid, and parent dir fid.
* - Send data to server.
* - Handle errors.
* - Reorder vhash and dcaches in their hashes, using the newly acquired fid.
*/
int
afs_ProcessOpCreate(struct vcache *avc, struct vrequest *areq,
afs_ucred_t *acred)
{
char *tname = NULL, *ttargetName = NULL;
struct AFSStoreStatus InStatus;
struct AFSFetchStatus OutFidStatus, OutDirStatus;
struct VenusFid pdir_fid, newFid;
struct AFSCallBack CallBack;
struct AFSVolSync tsync;
struct vcache *tdp = NULL, *tvc = NULL;
struct dcache *tdc = NULL;
struct afs_conn *tc;
struct rx_connection *rxconn;
afs_int32 hash, new_hash, index;
afs_size_t tlen;
int code, op = 0;
XSTATS_DECLS;
tname = afs_osi_Alloc(AFSNAMEMAX);
if (!tname)
return ENOMEM;
code = afs_GetParentVCache(avc, 0, &pdir_fid, tname, &tdp);
if (code)
goto end;
/* This data may also be in linkData, but then we have to deal with
* the joy of terminating NULLs and . and file modes. So just get
* it from the dcache where it won't have been fiddled with.
*/
if (vType(avc) == VLNK) {
afs_size_t offset;
struct dcache *tdc;
struct osi_file *tfile;
tdc = afs_GetDCache(avc, 0, areq, &offset, &tlen, 0);
if (!tdc) {
code = ENOENT;
goto end;
}
if (tlen > 1024) {
afs_PutDCache(tdc);
code = EFAULT;
goto end;
}
tlen++; /* space for NULL */
ttargetName = afs_osi_Alloc(tlen);
if (!ttargetName) {
afs_PutDCache(tdc);
return ENOMEM;
}
ObtainReadLock(&tdc->lock);
tfile = afs_CFileOpen(&tdc->f.inode);
code = afs_CFileRead(tfile, 0, ttargetName, tlen);
ttargetName[tlen-1] = '\0';
afs_CFileClose(tfile);
ReleaseReadLock(&tdc->lock);
afs_PutDCache(tdc);
}
/* Set status. */
InStatus.Mask = AFS_SETMODTIME | AFS_SETMODE | AFS_SETGROUP;
InStatus.ClientModTime = avc->f.m.Date;
InStatus.Owner = avc->f.m.Owner;
InStatus.Group = (afs_int32) afs_cr_gid(acred);
/* Only care about protection bits. */
InStatus.UnixModeBits = avc->f.m.Mode & 0xffff;
do {
tc = afs_Conn(&tdp->f.fid, areq, SHARED_LOCK, &rxconn);
if (tc) {
switch (vType(avc)) {
case VREG:
/* Make file on server. */
op = AFS_STATS_FS_RPCIDX_CREATEFILE;
XSTATS_START_TIME(op);
RX_AFS_GUNLOCK();
code = RXAFS_CreateFile(tc->id,
(struct AFSFid *)&tdp->f.fid.Fid,
tname, &InStatus,
(struct AFSFid *) &newFid.Fid,
&OutFidStatus, &OutDirStatus,
&CallBack, &tsync);
RX_AFS_GLOCK();
XSTATS_END_TIME;
break;
case VDIR:
/* Make dir on server. */
op = AFS_STATS_FS_RPCIDX_MAKEDIR;
XSTATS_START_TIME(op);
RX_AFS_GUNLOCK();
code = RXAFS_MakeDir(rxconn, (struct AFSFid *) &tdp->f.fid.Fid,
tname, &InStatus,
(struct AFSFid *) &newFid.Fid,
&OutFidStatus, &OutDirStatus,
&CallBack, &tsync);
RX_AFS_GLOCK();
XSTATS_END_TIME;
break;
case VLNK:
/* Make symlink on server. */
op = AFS_STATS_FS_RPCIDX_SYMLINK;
XSTATS_START_TIME(op);
RX_AFS_GUNLOCK();
code = RXAFS_Symlink(rxconn,
(struct AFSFid *) &tdp->f.fid.Fid,
tname, ttargetName, &InStatus,
(struct AFSFid *) &newFid.Fid,
&OutFidStatus, &OutDirStatus, &tsync);
RX_AFS_GLOCK();
XSTATS_END_TIME;
break;
default:
op = AFS_STATS_FS_RPCIDX_CREATEFILE;
code = 1;
break;
}
} else
code = -1;
} while (afs_Analyze(tc, rxconn, code, &tdp->f.fid, areq, op, SHARED_LOCK, NULL));
/* TODO: Handle errors. */
if (code) {
/* printf("afs_ProcessOpCreate: error while creating vnode on server, code=%d .\n", code); */
goto end;
}
/* The rpc doesn't set the cell number. */
newFid.Cell = avc->f.fid.Cell;
/*
* Change the fid in the dir entry.
*/
/* Seek the dir's dcache. */
tdc = afs_FindDCacheByFid(&tdp->f.fid);
if (tdc) {
/* And now change the fid in the parent dir entry. */
afs_dir_ChangeFid(tdc, tname, &avc->f.fid.Fid.Vnode, &newFid.Fid.Vnode);
afs_PutDCache(tdc);
}
if (vType(avc) == VDIR) {
/* Change fid in the dir for the "." entry. ".." has alredy been
* handled by afs_FixChildrenFids when processing the parent dir.
*/
tdc = afs_FindDCacheByFid(&avc->f.fid);
if (tdc) {
afs_dir_ChangeFid(tdc, ".", &avc->f.fid.Fid.Vnode,
&newFid.Fid.Vnode);
if (avc->f.m.LinkCount >= 2)
/* For non empty dirs, fix children's parentVnode and
* parentUnique reference.
*/
afs_FixChildrenFids(&avc->f.fid, &newFid);
afs_PutDCache(tdc);
}
}
/* Recompute hash chain positions for vnode and dcaches.
* Then change to the new FID.
*/
/* The vcache goes first. */
ObtainWriteLock(&afs_xvcache, 735);
/* Old fid hash. */
hash = VCHash(&avc->f.fid);
/* New fid hash. */
new_hash = VCHash(&newFid);
/* Remove hash from old position. */
/* XXX: not checking array element contents. It shouldn't be empty.
* If it oopses, then something else might be wrong.
*/
if (afs_vhashT[hash] == avc) {
/* First in hash chain (might be the only one). */
afs_vhashT[hash] = avc->hnext;
} else {
/* More elements in hash chain. */
for (tvc = afs_vhashT[hash]; tvc; tvc = tvc->hnext) {
if (tvc->hnext == avc) {
tvc->hnext = avc->hnext;
break;
}
}
} /* if (!afs_vhashT[i]->hnext) */
QRemove(&avc->vhashq);
/* Insert hash in new position. */
avc->hnext = afs_vhashT[new_hash];
afs_vhashT[new_hash] = avc;
QAdd(&afs_vhashTV[VCHashV(&newFid)], &avc->vhashq);
ReleaseWriteLock(&afs_xvcache);
/* Do the same thing for all dcaches. */
hash = DVHash(&avc->f.fid);
ObtainWriteLock(&afs_xdcache, 743);
for (index = afs_dvhashTbl[hash]; index != NULLIDX; index = hash) {
hash = afs_dvnextTbl[index];
tdc = afs_GetValidDSlot(index);
ReleaseReadLock(&tdc->tlock);
if (afs_indexUnique[index] == avc->f.fid.Fid.Unique) {
if (!FidCmp(&tdc->f.fid, &avc->f.fid)) {
/* Safer but slower. */
afs_HashOutDCache(tdc, 0);
/* Put dcache in new positions in the dchash and dvhash. */
new_hash = DCHash(&newFid, tdc->f.chunk);
afs_dcnextTbl[tdc->index] = afs_dchashTbl[new_hash];
afs_dchashTbl[new_hash] = tdc->index;
new_hash = DVHash(&newFid);
afs_dvnextTbl[tdc->index] = afs_dvhashTbl[new_hash];
afs_dvhashTbl[new_hash] = tdc->index;
afs_indexUnique[tdc->index] = newFid.Fid.Unique;
memcpy(&tdc->f.fid, &newFid, sizeof(struct VenusFid));
} /* if fid match */
} /* if uniquifier match */
if (tdc)
afs_PutDCache(tdc);
} /* for all dcaches in this hash bucket */
ReleaseWriteLock(&afs_xdcache);
/* Now we can set the new fid. */
memcpy(&avc->f.fid, &newFid, sizeof(struct VenusFid));
end:
if (tdp)
afs_PutVCache(tdp);
afs_osi_Free(tname, AFSNAMEMAX);
if (ttargetName)
afs_osi_Free(ttargetName, tlen);
return code;
}
